In a manufacturing process of a semiconductor device, a semiconductor wafer (hereinafter simply referred to as “wafer”) as a substrate to be processed is subjected to film formation, oxidative diffusion, modification and various kinds of heat treatments such as annealing and the like. To meet high-speed and high-integration requirements in the semiconductor devices, the annealing performed after ion implantation requires high-speed heating and cooling for the purpose of minimizing diffusion. As an annealing apparatus capable of performing the high-speed heating and cooling, there has been proposed an annealing apparatus that employs LEDs (Light-Emitting Diodes) as a heating source (see, e.g., Patent Document 1).
In case the LEDs are used as a heating source of the annealing apparatus, there is a need to generate a great light energy in keeping with the rapid heating. This makes it necessary to mount the LEDs in high density.
However, it is known that heat (heat generation) reduces the light emission amount of the LEDs. Therefore, if the influence of the heat generated in the LEDs (i.e., the influence of the input energy not converted to light) grows heavier by the high-density mounting of the LEDs, it is difficult to obtain an enough light emission amount from the LEDs. Thus far, no way is known to effectively cool the LEDs and to allow them to make a stable performance.
In addition, the annealing apparatus described above employs a multiplicity of LEDs and therefore has a complicated power supply mechanism. Thus, there is a need for a simple and easy-to-use power supply mechanism.